Suspension apparatus of vehicle

ABSTRACT

The invention provides a suspension apparatus of a vehicle comprising a base end portion of a swing arm pivotally attached to a vehicle body so as to freely oscillate, and a wheel which is rotatably supported to a leading end portion of the swing arm. A first link is pivotally attached to a portion between the base end portion and the leading end portion of the swing arm. A second link is pivotally attached to a position which is below a pivot point to which the base end portion of the swing arm is pivotally attached in the vehicle body, and the first link and the second link are pivotally attached. One end of a cushion unit is pivotally attached to the vehicle body. Another end of the cushion unit is pivotally attached to one of the first link and the second link, in which the first link or the second link comprises an expandable link. The expandable link is energized in a contracting direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a suspension apparatus of a vehicle inwhich a cushion unit (a hydraulic shock absorber) is provided between avehicle body and a swing arm.

2. Description of the Related Art

In a conventional suspension apparatus of a vehicle, as described inJapanese Patent Publication No. 59-29468 (JP-B), there is a structure inwhich a base end portion of a swing arm is pivotally attached to avehicle body so as to freely oscillate. A wheel is rotatably supportedto a leading end portion of the swing arm. A first link is pivotallyattached to a portion between the base end portion and the leading endportion of the swing arm. A second link is pivotally attached to aposition which is below a pivot point to which the base end portion ofthe swing arm is pivotally attached in the vehicle body. The first linkand the second link are pivotally attached. One end of a cushion unit ispivotally attached to the vehicle body, and another end of the cushionunit is pivotally attached to one of the first link and the second link.

In another conventional suspension apparatus of a vehicle, as describedin Japanese Patent Application Laid-open No. 2002-68066 (JP-A), there isa structure in which a base end portion of a swing arm is pivotallyattached to a vehicle body so as to freely oscillate. A wheel isrotatably supported to a leading end portion of the swing arm. A firstlink is pivotally attached to a portion between the base end portion andthe leading end portion of the swing arm. A second link is pivotallyattached to a position which is below a pivot point to which the baseend portion of the swing arm is pivotally attached in the vehicle body.The first link and the second link are pivotally attached. One end of acushion unit is pivotally attached to the swing arm, and another end ofthe cushion unit is pivotally attached to one of the first link and thesecond link.

In the suspension apparatus of the vehicle in accordance with JP-B59-29468 and JP-A 2002-68066, it is intended to secure a road holdingproperty of a wheel on the basis of a damping property of the cushionunit. However, there is a case that a following characteristic in anelongating direction is deteriorated due to an elongation side dampingforce. In other words, in the case that a load applied to the wheel (arear wheel) from the road surface is reduced while running on a roadsurface gap or braking, the wheel leaves the road surface, so that thereis a risk that driving force is reduced and stability of the vehicle isdeteriorated.

SUMMARY OF THE INVENTION

An object of the present invention is to improve a road surfacefollowing property or road holding of a wheel in a suspension apparatusof a vehicle in which a cushion unit is provided between a vehicle bodyand a swing arm.

The present invention relates to a suspension apparatus of a vehiclestructured such that a base end portion of a swing arm is pivotallyattached to a vehicle body so as to freely oscillate, and a wheel isrotatably supported to a leading end portion of the swing arm. A firstlink is pivotally attached to a portion between the base end portion andthe leading end portion of the swing arm. A second link is pivotallyattached to a position which is below a pivot point to which the baseend portion of the swing arm is pivotally attached in the vehicle body.The first link and the second link are pivotally attached. One end of acushion unit is pivotally attached to the vehicle body, and another endof the cushion unit is pivotally attached to one of the first link andthe second link. The first link or the second link is an expandablelink, and the expandable link is in an expandable manner and isenergized in a contracting direction.

The present invention relates to a suspension apparatus of a vehiclecomprising a base end portion of a swing arm pivotally attached to avehicle body so as to freely oscillate, and a wheel rotatably supportedto a leading end portion of the swing arm. A first link is pivotallyattached to a portion between the base end portion and the leading endportion of the swing arm. A second link is pivotally attached to aposition which is below a pivot point to which the base end portion ofthe swing arm is pivotally attached in the vehicle body. The first linkand the second link are pivotally attached. One end of a cushion unit ispivotally attached to the swing arm, and another end of the cushion unitis pivotally attached to one of the first link and the second link. Thefirst link or the second link comprises an expandable link, and theexpandable link is in an expandable manner and is energized in acontracting direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood from the detaileddescription given below and from the accompanying drawings which shouldnot be taken to be a limitation on the invention, but are forexplanation and understanding only.

The drawings:

FIG. 1 is a schematic view showing a motor cycle to which the presentinvention is applied;

FIG. 2 is a schematic view showing an assembled state of a suspensionapparatus in accordance with an embodiment 1;

FIGS. 3A and 3B show an operating state of the suspension apparatus inaccordance with the embodiment 1, in which FIG. 3A is a schematic viewshowing an upward moving state of the swing arm, and FIG. 3B is aschematic view showing a downward moving state of the swing arm;

FIG. 4 is a schematic view showing the assembled state and the swing armupward moving state of the embodiment 1 in an overlapping manner;

FIG. 5 is a schematic view showing the assembled state and the swing armdownward moving state of the embodiment 1 in an overlapping manner;

FIG. 6 is a schematic view showing an expandable link;

FIGS. 7A and 7B show a suspension apparatus in accordance with anembodiment 2, in which FIG. 7A is a schematic view showing an assembledstate and FIG. 7B is a schematic view showing a downward moving state ofa swing arm;

FIGS. 8A and 8B show a suspension apparatus in accordance with anembodiment 3, in which FIG. 8A is a schematic view showing an assembledstate and FIG. 8B is a schematic view showing a downward moving state ofa swing arm;

FIGS. 9A and 9B show a suspension apparatus in accordance with anembodiment 4, in which FIG. 9A is a schematic view showing an assembledstate and FIG. 9B is a schematic view showing a downward moving state ofa swing arm; and

FIG. 10 is a schematic view showing a suspension apparatus in accordancewith an embodiment 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1—FIGS. 1 to 6

A motor cycle 10 is structured, as shown in FIG. 1, such that a frontfork 13 and a front wheel 14 are mounted to a head pipe 12 provided in afront end portion of a frame 11 corresponding to a vehicle body side soas to be freely steered. A power unit 15 comprising an engine and atransmission and corresponding to the vehicle body side is mounted to alower portion of the frame 11. A rear wheel 16 is mounted to a rearportion of the power unit 15 via a swing arm type suspension apparatus20 in accordance with the present invention.

The suspension apparatus 20 comprises, as shown in FIG. 2, a base endportion of a swing arm 21 pivotally attached to the rear portion of thepower unit 15 via a pivot shaft 21A so as to be freely oscillated. Therear wheel 16 is supported to a leading end portion of the swing arm 21via an axle 21B so as to be freely rotated.

The suspension apparatus 20 comprises a first link 30 pivotally attachedto a lower bracket 22 provided in a lower portion of the swing arm 21between the base end portion (the pivot shaft 21A) and the leading endportion (the axis 21B) of the swing arm 21, via a connection shaft 21C.The connection shaft 21C is arranged below a line obtained by connectingthe pivot shaft 21A to the axle 21B.

The suspension apparatus 20 comprises a second link 40 pivotallyattached to a position below a pivot point (the pivot shaft 21A) towhich the base end portion of the swing arm 21 in the power unit 15 ispivotally attached, via a connection shaft 40A. The first link 30 andthe second link 40 are pivotally attached via a connection shaft 40B.

The suspension apparatus 20 comprises an upper end of a cushion unit (ahydraulic shock absorber) 50 pivotally attached to the frame 11 via aconnection shaft 50A, and a lower end of the cushion unit 50 pivotallyattached to the first link 30 via a connection shaft 50B. The connectionshaft 50A is arranged above the pivot shaft 21A of the power unit 15.

The cushion unit 50 has a cylinder 51. A piston rod 52 is inserted intothe cylinder 51, and is structured such that the cylinder 51 is mountedto the connection shaft 50A, and the piston rod 52 is mounted to theconnection shaft 50B. The cushion unit 50 is provided with a suspensionspring 53 comprising a compression coil spring between the cylinder 51and the piston rod 52, and buffers an impact force which is applied tothe vehicle from it's interaction with a road surface, on the basis ofan expansion and contraction of the suspension spring 53. The cushionunit 50 comprises a working fluid sealed within the cylinder 51.Expansion side and compression side damping force generating apparatusesare provided in a piston 54 or the like arranged in an insertion end ofthe piston rod 52 to the cylinder 51, and damps an expanding andcontracting vibration of the suspension spring 53.

Accordingly, in the suspension apparatus 20, the second link 40 isstructured as an expandable link 60. The expandable link 60 can beexpanded and contracted, and is energized in a contracting direction.

The expandable link 60 has a cylinder 61 and a piston rod 62 which isinserted into the cylinder 61 in a telescopic manner, as shown in FIG.6, and comprises a hydraulic damper in which a working fluid is sealedwithin the cylinder 61. The expandable link 60 comprises a compressioncoil spring 65 energizing in a direction that the cylinder 61 and thepiston rod 62 are contracted with each other and being internallyprovided between a rod guide 63 sealed in an opening end of the cylinder61 and being provided for the piston rod 62. A piston 64 is provided inan insertion end of the piston rod 62 to the cylinder 61. The expandablelink 60 is provided with an expansion side damping force generatingmeans 66 provided in an oil passage communicating two oil chambers 61Aand 61B sectioned in an inner portion of the cylinder 61 by the piston64 and comprises an orifice in the piston 64, and a check valve 67provided in an oil passage communicating two oil chambers 61A and 61Bbypassing the expansion side damping force generating means 66 duringcompression. The expansible link 60 comprises a stopper rubber 68Aregulating an expanded end position of the piston 64 arranged in the oilchamber 61A to which the piston rod 62 is inserted in the inner portionof the cylinder 61, in a state of being backed up by a collar 68B. Astopper rubber 69A regulating a compressed end position of the piston 64is arranged in the opposite side oil chamber 61B. In other words, theexpandable link 60 is energized by a spring force of the spring 65 inthe contracting direction, and has a damping force or a rebound force inthe expanding direction.

The expandable link 60 has a minimum length in a free state on the basisof the spring force of the spring 65.

The suspension apparatus 20 comprises the piston rod 62 of theexpansible link 60 (the second link 40) is connected to the power unit15 via the connection shaft 40A. The cylinder 61 is connected to thefirst link 30 via the connection shaft 40B, and the expandable link 60is set to a maximum expanded state (FIG. 6) in a state of beingassembled in the vehicle, a state in which a load of a rider or the likeis not applied.

A description will be given below of the operation and effect of thesuspension apparatus 20 in accordance with an embodiment 1.

(a) In the case that the rider rides on the vehicle or the vehicle runsagainst a projection on the road surface, whereby the swing arm 21 ismoved upward (FIG. 4) from an assembled state in FIG. 2 to an upwardmoved state in FIG. 3A, the expandable link 60 which is already in it'smost expanded position is regulated in the expansion in the axialdirection so as to be a rigid body in the axial direction, and carriesout a compression motion of the cushion unit 50.

In the case that the load applied to the rear wheel 16 from the roadsurface is reduced while running along the road surface gap (the recess)or while braking the vehicle, the expansion of the cushion unit 50delays due to the existence of the expansion side damping forcegenerating means when the swing arm 21 is going to move downward. Theswing arm 21 is thereby not moved downward. The expandable link 60 iscontracted at a moment on the basis of the energizing force in thecontracting direction so as to pull the swing arm 21 to a lower side. Atthis time, the pivot point (the connection shaft 50B) in the lower endportion of the cushion unit 50 does not move. The swing arm 21 movesdownward to the downward position in FIG. 3B from the assembled state inFIG. 2 (FIG. 5). Accordingly, the rear wheel 16 is in contact with theroad surface. It is possible to avoid a reduction of the driving force,and it is possible to maintain stability of the vehicle.

(b) The expandable link 60 is energized in the contracting direction,and is kept at a minimum length in the free state. However, it is keptat a maximum length on the basis of the spring force of the suspensionspring 53 of the cushion unit 50 or the like in a state of beingassembled in the vehicle. Accordingly, when the rider rides on thevehicle, the vehicle runs against the projection on the road surface andthe swing arm 21 moves upward as described in the item (a) mentionedabove. The expandable link 60 is securely regulated in expansion in theaxial direction so as to be a rigid body in the axial direction. Therebycompressing the cushion unit 50.

(c) The expandable link 60 generates the expansion side damping forceduring a period that the swing arm 21 moves downward in accordance withthe item (a) mentioned above. The rear wheel 16 gets free of the recesson the road surface after being in contact with the recess on the roadsurface, and the swing arm 21 again moves upward. In other words, duringa period that the expansible link 60 is extended from the contractedstate to the assembled state to the vehicle, the maximum length state.Accordingly, the expandable link 60 absorbs an upthrow input from theroad surface, and improves ride quality. Further, it is possible toprevent the impact generated when the expandable link 60 is fullyexpanded, the piston rod 62 being prevented from coming into collisionwith the rod guide 63 of the cylinder 61.

(d) Since the expansible link 60 is provided with the means (the checkvalve 67) for bypassing the extension side damping force generatingmeans 66 during compression, the expandable link 60 is rapidly set tothe contracted state when the swing arm 21 moves downward in accordancewith the item (a) mentioned above. It is thereby possible to secure theroad holding or the road surface following property of the rear wheel16.

(e) Since the expandable link 60 is internally provided with the spring65 energizing in the contracting direction of the cylinder 61, it ispossible to improve operability of the expandable link 60.

(f) The expandable link 60 can easily assemble the expansion sidedamping force generating means 66 and the bypassing means thereof, bystructuring the hydraulic damper.

Embodiment 2—FIGS. 7A and 7B

A suspension apparatus 20 in accordance with an embodiment 2 shown inFIGS. 7A and 7B is different from the suspension apparatus 20 inaccordance with the embodiment 1 in that the upper end of the cushionunit 50 is pivotally attached to an upper bracket 23 provided in anupper portion of the swing arm 21 in place of the frame 1, via theconnection shaft 50A. The connection shaft 50A is arranged above a lineconnecting the pivot shaft 21A to the axle 21B.

In accordance with the suspension apparatus 20 of the embodiment 2, thefollowing operations and effects are achieved.

In the case that the rider rides on the vehicle or the vehicle runsagainst a projection on the road surface, whereby the swing arm 21 ismoved upward from an assembled state in FIG. 7A to an upward movedstate, not shown, the expandable link 60 which is already completelyexpanded is regulated in the expansion of the axial direction so as tobe a rigid body in the axial direction, and carries out a compressionmotion of the cushion unit 50.

In the case that the load applied to the rear wheel 16 from the roadsurface is reduced while running on the road surface gap (the recess) orduring braking of the vehicle, the expansion of the cushion unit 50delays due to the existence of the expansion side damping forcegenerating means when the swing arm 21 is going to move downward,whereby the swing arm 21 is not moved downward. The expandable link 60is contracted on the basis of the energizing force in the contractingdirection so as to pull the swing arm 21 to a lower side, at this time,the pivot point in the lower end portion of the cushion unit 50 (theconnection shaft 50B) does not move. The swing arm 21 moves downward tothe downward position in FIG. 7B from the assembled state in FIG. 7A.Accordingly, the rear wheel 16 is in contact with the road surface. Itis possible to avoid a reduction of the driving force. It is alsopossible to maintain stability of the vehicle.

Further, in accordance with the suspension apparatus 20 of theembodiment 2, the same operations and effects as the operations andeffects (b) to (f) of the embodiment 1 are achieved.

Embodiment 3—FIGS. 8A and 8B

A suspension apparatus 20 in accordance with an embodiment 3 shown inFIGS. 8A and 8B is different from the suspension apparatus 20 inaccordance with the embodiment 2 in that the lower end of the cushionunit 50 is pivotally attached to the second link 40 in place of thefirst link 30, via the connection shaft 50B, and that the first link 30comprises an expandable link 60.

In accordance with the suspension apparatus 20 of the embodiment 3, thefollowing operations and effects are achieved.

In the case that the rider rides on the vehicle or the vehicle runsagainst a projection on the road surface, whereby the swing arm 21 ismoved upward from an assembled state in FIG. 8A to an upward position,not shown, the expandable link 60 which is already in the maximumexpansion position is regulated in it's expansion in the axial directionso as to be a rigid body in the axial direction, and thereby carries outa compression motion of the cushion unit 50.

In the case that the load applied to the rear wheel 16 from the roadsurface is reduced while running along a road surface gap (the recess)or when braking the vehicle, the expansion of the cushion unit 50 delaysdue to the existence of the expansion side damping force generatingmeans when the swing arm 21 is going to move downward, whereby the swingarm 21 is not moved downward. The expandable link 60 is contracted onthe basis of the energizing force in the contracting direction so as topull the swing arm 21 to a lower side, at this time, the pivot point inthe lower end portion of the cushion unit 50 (the connection shaft 50B)does not move, and the swing arm 21 moves downward to the downwardposition in FIG. 8B from the assembled state in FIG. 8A. Accordingly,the rear wheel 16 is in contact with the road surface. It is therebypossible to avoid reduction of the driving force, and it is possible tomaintain stability of the vehicle.

Further, in accordance with the suspension apparatus 20 of theembodiment 3, the same operations and effects as the operations andeffects (b) to (f) of the embodiment 1 are achieved.

Embodiment 4—FIGS. 9A and 9B

A suspension apparatus 20 in accordance with an embodiment 4 shown inFIGS. 9A and 9B is different from the suspension apparatus 20 inaccordance with the embodiment 1 in that the lower end of the cushionunit 50 is pivotally attached to the second link 40 in place of thefirst link 30, via the connection shaft 50B, and that the first link 30comprises an expandable link 60.

The second link 40 comprises a bell crank. The connection shaft 40Bbetween the first link 30 (the expansible link 60) and the second link40 is arranged at the midpoint of the connection shaft 40A between thesecond link 40 and the power unit 15, and the connection shaft 50Bbetween the second link 40 and the cushion unit 50.

In accordance with the suspension apparatus 20 of the embodiment 4, thefollowing operations and effects are achieved.

In the case that the rider rides on the vehicle or the vehicle runsagainst a projection on the road surface, whereby the swing arm 21 ismoved upward from an assembled state in FIG. 9A to an upward position,not shown, the expandable link 60 which is already completely expandedis regulated in its expansion in the axial direction so as to be a rigidbody in the axial direction, and carries out a compression motion of thecushion unit 50.

In the case that the load applied to the rear wheel 16 from the roadsurface is reduced while running along road surface gap (the recess) orwhen braking the vehicle, the expansion of the cushion unit 50 delaysdue to the existence of the expansion side damping force generatingmeans when the swing arm 21 is going to move downward. Whereby the swingarm 21 is not moved downward. The expandable link 60 is contracted at amoment on the basis of the energizing force in the contracting directionso as to pull the swing arm 21 to a lower side. At this time, the pivotpoint in the lower end portion of the cushion unit 50 (the connectionshaft 50B) does not move, and the swing arm 21 moves downward to thedownward position in FIG. 9B from the assembled state in FIG. 9A.Accordingly, the rear wheel 16 is in contact with the road surface. Itis possible to avoid a reduction of the driving force, and it ispossible to maintain stability of the vehicle.

Further, in accordance with the suspension apparatus 20 of theembodiment 4, the same operations and effects as the operations andeffects (b) to (f) of the embodiment 1 are achieved.

Embodiment 5—FIG. 10

A suspension apparatus 20 in accordance with an embodiment 5 shown inFIG. 10 is different from the suspension apparatus 20 in accordance withthe embodiment 1 in that the first link 30 is pivotally attached to theupper bracket 24 of the swing arm 21 between the base end portion (thepivot shaft 21A) and the leading end portion (the axle 21B) of the swingarm 21, via the connection shaft 21C. The connection shaft 21C isarranged above the line connecting the pivot shaft 21A to the axle 21B.The upper end of the cushion unit 50 is pivotally attached to the firstlink 30 via the connection shaft 50A where the connection shaft 50A isarranged above the line connecting the pivot shaft 21A to the axle 21B.The lower end of the cushion unit 50 is pivotally attached to the lowerbracket 25 of the swing arm 21 between the base end portion (the pivotshaft 21A) and the leading end portion (the axle 21B) of the swing arm21, via the connection shaft 50B. The connection shaft 50B is arrangedbelow the line connecting the pivot shaft 21A to the axle 21B. Thesecond link 40 is connected to a portion between the connection shaft21C to the swing arm 21 in the first link 30 via the connection shaft40B, and the connection shaft 50A to the cushion unit 50.

In accordance with the suspension apparatus 20 of the embodiment 5, thefollowing operations and effects are achieved.

In the case that the rider rides on the vehicle or the vehicle runsagainst a projection on the road surface, whereby the swing arm 21 ismoved upward from an assembled state, the expandable link 60 which isalready completely expanded is regulated in the expansion in the axialdirection so as to be a rigid body in the axial direction, and carriesout a compression motion of the cushion unit 50.

In the case that the load applied to the rear wheel 16 from the roadsurface is reduced while running along the road surface gap (the recess)or when braking the vehicle, the expansion of the cushion unit 50 delaysdue to the existence of the expansion side damping force generatingmeans when the swing arm 21 is going to move downward, whereby the swingarm 21 is not moved downward. The expandable link 60 is contracted at amoment on the basis of the energizing force in the contracting directionso as to pull the swing arm 21 to a lower side. At this time, the pivotpoint in the lower end portion of the cushion unit 50 (the connectionshaft 50B) does not move, and the swing arm 21 moves downward from theassembled state. Accordingly, the rear wheel 16 is in contact with theroad surface. It is possible to avoid a reduction of the driving force,and it is possible to maintain stability of the vehicle.

Further, in accordance with the suspension apparatus 20 of theembodiment 5, the same operations and effects as the operations andeffects (b) to (f) of the embodiment 1 are achieved.

In this case, in the present invention, the expandable link 60 may beprovided between the connection shaft 21C to the swing arm 21 in thefirst link 30 to which the cushion unit 50 is pivotally attached, andthe connection shaft 40 to the second link 40, or between the connectionshaft 40A to the vehicle body side in the second link 40 to which thecushion unit 50 is pivotally attached, and the connection shaft 40B tothe first link 30. In this case, it is preferable that the first link 30or the second link 40 to which the cushion unit 50 is not pivotallyattached is comprises the expansible link 60.

As heretofore explained, embodiments of the present invention have beendescribed in detail with reference to the drawings. However, thespecific configurations of the present invention are not limited to theillustrated embodiments but those having a modification of the designwithin the range of the presently claimed invention are also included inthe present invention.

Although the invention has been illustrated and described with respectto several exemplary embodiments thereof, it should be understood bythose skilled in the art that the foregoing and various other changes,omissions and additions may be made to the present invention withoutdeparting from the spirit and scope thereof. Therefore, the presentinvention should not be understood as limited to the specific embodimentset out above, but should be understood to include all possibleembodiments which can be encompassed within a scope of equivalentsthereof with respect to the features set out in the appended claims.

1. A suspension apparatus of a vehicle comprising: a base end portion ofa swing arm pivotally attached to a vehicle body so as to freelyoscillate, a wheel rotatably supported to a leading end portion of theswing arm; a first link pivotally attached to a portion between the baseend portion and the leading end portion of the swing arm, a second linkpivotally attached to a position which is below a pivot point to whichthe base end portion of the swing arm is pivotally attached in thevehicle body, the first link and the second link being pivotallyattached; one end of a cushion unit is pivotally attached to the vehiclebody, and another end of the cushion unit is pivotally attached to oneof the first link and the second link, wherein the first link or thesecond link comprises an expandable link, and the expandable link ispositionable in an expandable position and is energized in a contractingdirection.
 2. A suspension apparatus of a vehicle comprising: a base endportion of a swing arm pivotally attached to a vehicle body so as tofreely oscillate, a wheel rotatably supported to a leading end portionof the swing arm; a first link pivotally attached to a portion betweenthe base end portion and the leading end portion of the swing arm, asecond link pivotally attached to a position which is below a pivotpoint to which the base end portion of the swing arm is pivotallyattached in the vehicle body, the first link and the second link beingpivotally attached; one end of a cushion unit is pivotally attached tothe swing arm, and another end of the cushion unit is pivotally attachedto one of the first link and the second link, wherein the first link orthe second link comprises an expandable link, and the expandable link ispositionable in an expandable position and is energized in a contractingdirection.
 3. A suspension apparatus of a vehicle as claimed in claim 1,wherein the expandable link achieves maximum expansion when assembled inthe vehicle.
 4. A suspension apparatus of a vehicle as claimed in claim2, wherein the expandable link achieves maximum expansion when assembledin the vehicle.
 5. A suspension apparatus of a vehicle as claimed inclaim 1, wherein the expandable link comprises an expansion side dampingforce generating means.
 6. A suspension apparatus of a vehicle asclaimed in claim 2, wherein the expandable link comprises an expansionside damping force generating means.
 7. A suspension apparatus of avehicle as claimed in claim 5, wherein the expandable link comprises ameans for bypassing the expansion side damping force generating meansduring compression.
 8. A suspension apparatus of a vehicle as claimed inclaim 6, wherein the expandable link comprises a means for bypassing theexpansion side damping force generating means during compression.
 9. Asuspension apparatus of a vehicle as claimed in claim 1, wherein theexpandable link comprises a piston rod insertable in a cylinder, and aspring energizing the cylinder and the piston rod in a contractingdirection with each other internally provided in the cylinder.
 10. Asuspension apparatus of a vehicle as claimed in claim 2, wherein theexpandable link comprises a piston rod insertable in a cylinder, and aspring energizing the cylinder and the piston rod in a contractingdirection with each other internally provided in the cylinder.
 11. Asuspension apparatus of a vehicle as claimed in claim 5, wherein theexpandable link comprises a hydraulic damper.
 12. A suspension apparatusof a vehicle as claimed in claim 6, wherein the expandable linkcomprises a hydraulic damper.
 13. A suspension apparatus of a vehicle asclaimed in claim 9, wherein the spring comprises a coil spring which isprovided between a rod guide for the piston rod sealed in an opening endof the cylinder, and a piston provided in an insertion end of the pistonrod with respect to the cylinder.
 14. A suspension apparatus of avehicle as claimed in claim 10, wherein the spring comprises a coilspring which is provided between a rod guide for the piston rod sealedin an opening end of the cylinder, and a piston provided in an insertionend of the piston rod with respect to the cylinder.
 15. A suspensionapparatus of a vehicle as claimed in claim 5, wherein the expandablelink comprises the piston rod being insertable in the cylinder, thepiston being provided in the insertion end of the piston rod withrespect to the cylinder, and the expansion side damping force generatingmeans being provided in the piston, and comprising an orifice which isprovided in an oil passage communicating two oil chambers sectioned inan inner portion of the cylinder by the piston.
 16. A suspensionapparatus of a vehicle as claimed in claim 6, wherein the expandablelink comprises the piston rod being insertable in the cylinder, thepiston being provided in the insertion end of the piston rod withrespect to the cylinder, the expansion side damping force generatingmeans being provided in the piston, comprising an orifice which isprovided in an oil passage communicating two oil chambers sectioned inan inner portion of the cylinder by the piston.
 17. A suspensionapparatus of a vehicle as claimed in claim 7, wherein the expandablelink comprises the piston rod insertable in the cylinder, the pistonprovided in the insertion end of the piston rod with respect to thecylinder, and the means for bypassing the expansion side damping forcegenerating means during compression being provided in the piston,comprising a check valve which is provided in an oil passagecommunicating two oil chambers sectioned in an inner portion of thecylinder by the piston.
 18. A suspension apparatus of a vehicle asclaimed in claim 8, wherein the expandable link comprises the piston rodinsertable the cylinder, the piston being provided in the insertion endof the piston rod with respect to the cylinder, and the means forbypassing the expansion side damping force generating means duringcompression being provided in the piston, comprising a check valve whichis provided in an oil passage communicating two oil chambers sectionedin an inner portion of the cylinder by the piston.
 19. A suspensionapparatus of a vehicle as claimed in claim 15, wherein the expandablelink comprises a first stopper rubber regulating an expanded endposition of the piston arranged in one side oil chamber to which thepiston rod is inserted in the inner portion of the cylinder, and asecond stopper rubber regulating a compressed end position of the pistonbeing arranged in another side oil chamber.
 20. A suspension apparatusof a vehicle as claimed in claim 17, wherein the expandable linkcomprises a first stopper rubber regulating an expanded end position ofthe piston arranged in one side oil chamber to which the piston rod isinserted in the inner portion of the cylinder, and a second stopperrubber regulating a compressed end position of the piston being arrangedin another side oil chamber.